Surface modification of carbonaceous materials by introduction of gamma keto carboxyl containing functional groups

ABSTRACT

The present invention provides a method for the preparation of carbonaceous materials comprising a plurality of gamma-keto-carboxyl containing functional groups surface bonded thereto, and further provides several surface modified carbonaceous materials resulting therefrom.

FIELD OF THE INVENTION

[0001] The present invention relates to the surface modification ofvarious carbonaceous materials and compounds. More specifically, theinvention provides methods for the incorporation of gamma keto carboxylcontaining functional groups onto the surface of carbonaceous materialsand compounds and similarly provides several surface modifiedcarbonaceous materials and compounds resulting therefrom.

BACKGROUND OF THE INVENTION

[0002] The surface modification of carbonaceous materials has beenwidely explored as a means for achieving desired chemical and physicalproperties not normally exhibited by carbonaceous materials and/orcompounds. Recently, there has been a considerable interest in surfacemodification of carbonaceous materials for improved physicochemicalproperties in rubber, plastics, coatings and inks.

[0003] Traditionally, various additives, dispersants and surfactantswere used to improve properties of carbonaceous materials, such ascarbon black. However, these materials only provide marginal improvementin the desired properties and such additives can undesirably increasethe viscosity of resulting dispersions. Moreover, these additives addsignificant costs and are therefore economically unfavorable as well. Tothis end, the concept of surface modification of carbonaceous materialsby incorporating specific organic functional groups tends to achievemore desired results. For example, oxidation of carbon black generatessurface active hydroxy and carboxylic sites. However, in the past, theconcentration of these surface active sites has been very low, thusrendering the method ineffective for improving properties of thecarbonaceous materials. As such, existing oxidation methods only providemarginal improvements in desired properties

[0004] As an object of the present invention, a method has beendeveloped to chemically bond aliphatic and aromatic carboxylatefunctional groups to inactive carbon black surface sites with aresulting high level of concentration. These carboxylate functionalitiessurface bonded thereto advantageously provide for a good interactionwith substrates and therefore result in improved properties for use inrubber, plastics, coatings and ink applications.

SUMMARY OF THE INVENTION

[0005] Among other aspects, the present invention is based upon methodsfor the preparation of carbonaceous materials comprising a plurality ofgamma keto carboxyl containing functional groups surface bonded thereto,and further provides several inventive surface modified carbonaceousmaterials resulting therefrom.

[0006] In a first aspect, the present invention provides a surfacemodified carbonaceous material, comprising a plurality of gamma ketocarboxyl containing functional groups of the general formula—(CO)—CR¹R³—CR²R⁴—(CO)OM surface bonded thereto, wherein R¹, R², R³, andR⁴ independently or collectively represent hydrogen, hydroxyl, amino,trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, heterocycle,carbon-carbon bond, or aryl substituent, which substituents can besubstituted or unsubstituted, and wherein M is a hydrogen or a cationicspecies. Additionally, any one or more combination of R¹ and R², R¹ andR⁴, R³ and R² or R³ and R⁴ can collectively represent a carbon-carbonbond, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl,C₃-C₇ cycloalkenyl, heterocycle, or aryl substituent, which substituentcan be substituted or unsubstituted as well.

[0007] In a second aspect, the present invention also provides a processfor the manufacture of a surface modified carbonaceous materialcomprising a plurality of gamma-keto-carboxyl containing functionalgroups surface bonded thereto. Accordingly, the process comprises thesteps of introducing a carbonaceous material and an anhydride into asuitable solvent and then reacting the carbonaceous material with theanhydride under conditions effective to provide a surface modifiedcarbonaceous material comprising a plurality of gamma-keto-carboxylcontaining functional groups having the general formula—(CO)—CR¹R³—CR²R⁴—(CO)—OH surface bonded thereto, wherein R¹, R², R³,and R⁴ independently or collectively represent hydrogen, hydroxyl,amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, heterocycle,carbon-carbon bond, or aryl substituent, which substituents can besubstituted or unsubstituted.

[0008] In a third aspect, the invention provides products made from theprocesses of the invention.

[0009] In still a fourth aspect, the present invention further providesan aqueous composition, comprising the surface modified compounds,compositions and materials of the present invention and water.

[0010] Additional advantages of the invention will be obvious from thedescription, or may be learned by practice of the invention. Additionaladvantages of the invention will also be realized and attained by meansof the elements and combinations particularly pointed out in theappended claims. Therefore, it is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory of certain embodiments of the invention, andare not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE FIGURES

[0011] The appended Figures, which are incorporated in and constitutepart of the specification, illustrate the effectiveness of the processof the present invention to provide a surface modified carbonaceousmaterial having a plurality of gamma-keto-carboxylate functionalitiessurface bonded thereto.

[0012]FIG. 1 is a plot of the XPS spectrum of an unmodified carbon blackcompound (Raven 2500, manufactured by Columbian Chemical Company,Marietta, Ga., U.S.A.) indicating the cumulative percentage of surfaceconcentration of oxygenic species.

[0013]FIG. 2 is a plot of the XPS spectrum indicating the cumulativepercentage of surface concentration of oxygenic species present in acarbon black compound (Raven 2500, manufactured by Columbian ChemicalCompany, Marietta, Ga., U.S.A.) that has been surface modified withsuccinic anhydride.

[0014]FIG. 3 is a plot of the XPS spectrum indicating the cumulativepercentage of surface concentration of oxygenic species present in acarbon black compound (Raven 2500, manufactured by Columbian ChemicalCompany, Marietta, Ga., U.S.A.) that has been surface modified withphthalic anhydride.

[0015]FIG. 4 is a plot of the XPS spectrum for the oxygen regionmeasured in FIG. 1.

[0016]FIG. 5 is a plot of the XPS spectrum for the oxygen regionmeasured in FIG. 2.

[0017]FIG. 6 is a plot of the XPS spectrum for the oxygen regionmeasured in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention may be understood more readily by referenceto the following detailed description and any examples provided herein.It is also to be understood that this invention is not limited to thespecific embodiments and methods described below, as specific componentsand/or conditions may, of course, vary. Furthermore, the terminologyused herein is used only for the purpose of describing particularembodiments of the present invention and is not intended to be limitingin any way.

[0019] It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” comprise pluralreferents unless the context clearly dictates otherwise. For example,reference to a component in the singular is intended to comprise aplurality of components.

[0020] Ranges may be expressed herein as from “about” or “approximately”one particular value and/or to “about” or “approximately” anotherparticular value. When such a range is expressed, another embodimentcomprises from the one particular value and/or to the other particularvalue. Similarly, when values are expressed as approximations, by use ofthe antecedent “about,” it will be understood that the particular valueforms another embodiment.

[0021] As used herein, a weight percent of a component, unlessspecifically stated to the contrary, is based on the total weight of theformulation or composition in which the component is included.

[0022] As used herein, the term “alkyl” refers to a paraffinichydrocarbon group which may be derived from an alkane by dropping onehydrogen from the formula. Non-limiting examples include C₁-C₂₀ alkanederivatives such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,and isobutyl. To this end, it should be understood that an alkylsubstituent suitable for use in the present invention can be a branchedor straight chain alkyl substituent.

[0023] As used herein, the term “cycloalkyl” refers to a closed ringstructure comprised of an alkyl derivative as defined above. Althoughlarger structures are suitable with the present invention, a cycloalkylsubstituent will preferably be a C₃-C₇ cycloalkyl ring.

[0024] As used herein, the term “alkenyl” is intended to refer to asubstituent derived from the class of unsaturated hydrocarbons havingone or more double bonds. Those containing only one double bond arereferred to as alkenes or alkenyl substituents. Those with two or moredouble bonds are called alkadienes (alkadienyl), alkatrienes(alkatrienyl) and so on. Non-limiting examples include ethylene,propylene, butylene and the like. To this end, it should be understoodthat an alkenyl substituent suitable for use in the present inventioncan be substituted or unsubstituted.

[0025] As used herein, the term “cycloalkenyl” refers to a closed ringstructure comprised of an alkenyl derivative as defined above. Althoughlarger structures are suitable with the present invention, acycloalkenyl substituent will preferably be a C₃-C₇ cycloalkenyl ring

[0026] As used herein, the term “alkynyl” is intended to refer asubstituent derived from the class of unsaturated hydrocarbons havingone or more triple bonds.

[0027] As used herein, the term “cycloalkynyl” refers to a closed ringstructure comprised of an alkynyl derivative as defined above. Althoughlarger structures are suitable with the present invention, acycloalkynyl substituent will preferably be a C3-C7 cycloalkynyl ring.

[0028] As used herein, the term “aryl” refers to a compound orsubstituent whose molecules have the ring structure characteristic ofbenzene, naphthalene, phenanthrene, anthracene, and the like. That is tosay, an aryl group typically contains either the 6-carbon ring ofbenzene or the condensed 6 carbon rings of other aromatic derivatives.For example, an aryl group can be a phenyl or naphthyl group. To thisend, it should be understood that aryl substituents suitable for usewith the present invention can be substituted or unsubstituted.

[0029] As used herein, the term “heterocycle” refers to a closed ringsubstituent, preferably a 5 or 6 member ring, in which one or more ofthe atoms in the ring structure is an element other than carbon, e.g.,sulfur, nitrogen, oxygen and the like. Examples of a heterocylce orheterocyclic substituent include, without limitation, thiophene,pyridine, pyrole, furan, and purine.

[0030] As used herein, the term “flocculation” refers to the combinationor aggregation of suspended or dispersed particles in such a way thatthey form small clumps or agglomerates.

[0031] As used herein, the term “gamma-keto-carboxyl” refers to afunctional substituent of the general formula: —(CO)—CR¹R³—CR²R⁴—(CO)—OMwherein M is either hydrogen or a cationic species as defined herein. Asused herein, substituents R¹, R², R³, and R⁴ can be independentlyselected from hydrogen, hydroxyl, amino, trimethyl amino, sulfonate,C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent. Additionally, any one or morecombination of R¹ and R², R¹ and R⁴, R³ and R² or R³ and R⁴ cancollectively represent a carbon-carbon bond, C₁-C₂₀ alkyl, C₂-C₂₀alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl,heterocycle, or aryl substituent, which substituent can be substitutedor unsubstituted as well.

[0032] As used herein, the term “surface bonded” refers to a substituentthat is substantially bonded, either covalently or ionically, only tothe outer surface of the carbonaceous material particle. To this end, asubstituent that is “surface bonded” is substantially absent from theinner region or core of the carbonaceous material particle.

[0033] As used herein, the term “cationic species” refers to apositively charged molecular or elemental species capable of forming anionic bond with a carboxylate substituent. Although not required, it ispreferred that the cationic species have a single positive charge. Tothis end, examples of cationic species suitable for use with the presentinvention include, without limitation, ammonium; organic bases such asdimethylethanol amine (DMEA) and triethanol amine (TEA); and the group(I) alkali metals, e.g., lithium, sodium, potassium, rubidium, cesiumand francium. Alternatively, it will be understood that a cationicspecies with a positive charge greater that one will still work with thepresent invention but will bond or otherwise interact with a number ofgamma-keto-carboxyl containing functional groups equal to its positivecharge. That is to say, for example, the group (II) metals could also beused as suitable cationic species in the present invention, but it willbe understood that a group (II) metal would interact with twogamma-keto-carboxyl containing functional groups.

[0034] As used herein, the phrase “group (I) metals” refers to the classof metals including lithium, sodium, potassium, rubidium, cesium andfrancium.

[0035] As used herein, the phrase “group (II) metals” refers to theclass of metals including beryllium, magnesium, calcium, strontium,barium, and radium.

[0036] As used herein, the term “XPS” refers to X-ray PhotoelectronSpectroscopy. Accordingly, all XPS measurements disclosed herein havebeen conducted using the Physical Electronics 5802 Multitechnique withAl Kα X-ray source.

[0037] As used herein, the term “carbonaceous material” is intended toinclude, without limitation, i) carbonaceous compounds having a singledefinable structure; or ii) aggregates of carbonaceous particles,wherein the aggregate does not necessarily have a unitary, repeating,and/or definable structure or degree of aggregation. For example, acarbon black material as used herein can be a carbon black compoundhaving a definable structure or, alternatively, can also be an aggregateof carbonaceous particles wherein the exact structure or degree ofaggregation is unknown.

[0038] As used herein, the term “optional” or “optionally” means thatthe subsequently described event or circumstance may or may not occur,and that the description includes instances where said event orcircumstance occurs and instances where it does not. For example, thephrase “optionally substituted lower alkyl” means that the lower alkylgroup may or may not be substituted and that the description includesboth unsubstituted lower alkyl and lower alkyl where there issubstitution.

[0039] As used herein, by use of the term “effective,” “effectiveamount,” or “conditions effective to” it is meant that such amount orreaction condition is capable of performing the function of the compoundor property for which an effective amount is expressed. As will bepointed out below, the exact amount required will vary from oneembodiment to another, depending on recognized variables such as thecompounds employed and the processing conditions observed. Thus, it isnot always possible to specify an exact “effective amount” or “conditioneffective to.” However, it should be understood that an appropriateeffective amount will be readily determined by one of ordinary skill inthe art using only routine experimentation.

[0040] As initially set forth above, the present invention relates tomethods for the manufacture of surface modified carbonaceous materialscomprising a plurality of gamma-keto-carboxyl containing function groupssurface bonded thereto, and similarly provides several surface modifiedcarbonaceous materials resulting therefrom.

[0041] Accordingly, in a first aspect, the present invention provides amethod comprising the steps of first introducing a carbonaceous materialand a suitable anhydride into a suitable solvent. The carbonaceousmaterial is then reacted with the anhydride under conditions effectiveto provide a surface modified carbonaceous material comprising aplurality of gamma-keto-carboxyl containing functional groups having thegeneral formula —(CO)—CR¹R³—CR²R⁴—(CO)—OH surface bonded thereto,wherein R¹, R², R³, and R⁴ can be independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent. Additionally, any one or more combination of R¹and R², R¹ and R⁴, R³ and R² or R³ and R⁴ can collectively represent acarbon-carbon bond, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, heterocycle, or aryl substituent, whichsubstituent can be substituted or unsubstituted as well.

[0042] The process of the present invention can be used with a varietyof carbonaceous materials. To this end, any carbonaceous compound ormaterial can be used provided there are sufficient reactive edge sitescapable of interacting with the suitable anhydride component underconditions effective to provide a desired surface modified carbonaceousmaterial. Although not required, it is preferred that the carbonaceousmaterial have a surface area of at least approximately 25 m²/g asmeasured by ASTM-D4820. In a more preferred embodiment, when measured byASTM-D4820, the carbonaceous material will have a surface area of atleast approximately 100 m²/g. In still a more preferred embodiment, thesurface area of the carbonaceous material will be greater thanapproximately 200 m²/g when measured according to the ASTM-D4820 method.

[0043] Specific examples of suitable carbonaceous materials include,without limitation, carbon fiber, activated charcoal, finely dividedcarbon, carbon black, graphite, fullerinic carbons, and nanocarbons. Ina preferred embodiment, the carbonaceous material is a carbon blackhaving a surface area greater than approximately 200 m²/g and an oiladsorption rate of at least 60 ml/100 g as measured by ASTM-D2414.

[0044] Solvents that can be used with the present invention include anyorganic solvent known to one of ordinary skill in the art as suitablefor use in a Friedel-Crafts acylation reaction. To this end, preferredexamples include, without limitation, dimethylacetamide,dimethylsulfoxide and dimethylformamide.

[0045] Anhydrides that can be used in the process of the presentinvention include any organic anhydride suitable for use in aFriedel-Crafts acylation reaction. To this end, the anhydride can beeither an aromatic or an aliphatic anhydride.

[0046] In one embodiment, a preferred anhydride suitable for use withthe process includes, without limitation, a succinic anhydride of thegeneral formula:

[0047] In accordance with this embodiment, R¹ and R² are independentlyselected from hydrogen, hydroxyl, amino, trimethyl amino, sulfonate,C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent. Additionally, whereapplicable, substituents R¹ and R² can be substituted or unsubstitutedas well.

[0048] When the process of the present invention is carried out with asuccinic anhydride as set forth above, the resulting surface bondedgamma-keto-carboxyl containing functional group will be a succinic acidderivative having the general formula:

—(CO)—CHR¹—CHR²—(CO)—OH,

[0049] wherein R¹ and R² are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent, and wherein R¹ and R² the substituents can besubstituted or unsubstituted. To this end, in a preferred embodiment, R¹and R² each independently represent hydrogen atoms.

[0050] In another embodiment, a preferred anhydride suitable for usewith the process includes, without limitation, a maleic anhydride of thegeneral formula:

[0051] In accordance with this embodiment, R¹ and R² are independentlyselected from hydrogen, hydroxyl, amino, trimethyl amino, sulfonate,C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent. Additionally, whereapplicable, substituents R¹ and R² can be substituted or unsubstitutedas well.

[0052] When the process of the present invention is carried out with amaleic anhydride as set forth above, the resulting surface bondedgamma-keto-carboxyl containing functional group will be a maleic acidderivative having the general formula:

—(CO)—CR¹═CR²—(CO)—OH,

[0053] wherein R¹ and R² are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent, and wherein R¹ and R² the substituents can besubstituted or unsubstituted. To this end, in a preferred embodiment, R¹and R² each independently represent hydrogen atoms.

[0054] In still Another embodiment, a preferred anhydride suitable foruse with the process includes, without limitation, a phthalic anhydrideof the general formula:

[0055] In accordance with this embodiment, R⁵ and R⁶ can be positionedon any carbon within the six member ring and are independently selectedfrom hydrogen, hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent. Additionally, whereapplicable, substituents R⁵ and R⁶ can be substituted or unsubstitutedas well.

[0056] When a phthalic anhydride, as set forth above, is used with theprocess of the present invention, the resulting gamma-keto-carboxylcontaining function group surface bonded to the carbonaceous materialwill have the general structure:

[0057] wherein “X” represents the carbonaceous material. In addition, asdescribed above, R⁵ and R⁶ can again be positioned on any carbon withinthe six member ring and are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent. Also, where applicable, substituents R⁵ and R⁶can again be substituted or unsubstituted as well. To this end, in apreferred embodiment, R⁵ and R⁶ both represent hydrogen atoms.

[0058] It will be appreciated that the optimum reaction conditions forperforming the process of the present invention will, of course, varydepending on the particular anhydride, solvent, and/or the particularcarbonaceous material selected to be surface modified. To this end,arriving at such optimum conditions would be readily obtainable by oneof ordinary skill in the art or otherwise can be obtained through nomore than routine experimentation.

[0059] In one embodiment, the reaction conditions can further comprisethe presence of a suitable catalyst. To this end, any catalyst that isknown for use with a Friedel-Crafts acylation reaction may be used inthe process of the present invention. However, in a preferredembodiment, the catalyst is anhydrous aluminum chloride or ferricchloride. Furthermore, when used, the preferred amount of catalystrelative to the amount of anhydride in the reaction mixture should amolar ratio in the range of from approximately 0.8M to approximately1.2M. In still a more preferred embodiment, the molar ratio of catalystto the anhydride is approximately 1:1 or equimolar.

[0060] According to the invention, any amount of carbonaceous compoundcan be used provided it is present in adequate proportion to thesolvent, catalyst and anhydride in order to react accordingly. To thisend, in a preferred embodiment, the carbonaceous compound or material tobe surface modified is mixed with a suitable solvent such that theamount of carbonaceous compound relative to the solvent is a weightratio in the range of from approximately 1:2 to approximately 1:3.

[0061] Likewise, any amount of anhydride can be used in the reactionprovided it too is present in an adequate amount relative to thecarbonaceous material so that the reaction will proceed. To this end, ina preferred embodiment, the amount of anhydride introduced in to thereaction, relative to the amount of carbonaceous material is a weightratio of at least approximately 1:10.

[0062] Once the reaction mixture has been prepared, the reaction isallowed to proceed at room temperature for approximately 2 hours. It isunderstood that the reaction occurs relatively fast and therefore wouldlikely be complete prior to the completion of the 2 hour reaction time,however, it is also appreciated that by allowing the mixture to reactfor a period of time in excess of the actual reaction time merely helpsto ensure substantial completion of the reaction.

[0063] In another aspect of the present invention, it may be desired,although not required, to further treat the surface modifiedcarbonaceous materials as set forth above, with a neutralizing agent inorder to provide a surface modified carbonaceous material or compoundcomprising a plurality of gamma-keto-carboxyl containing functionalgroups having the general formula —(CO)—CR¹R³—CR²R⁴—(CO)—OM surfacebonded thereto, wherein M is a cationic species as defined herein andwherein R¹, R², R³, and R⁴ can be independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent. Additionally, any one or more combination of R¹and R², R¹ and R⁴, R³ and R² or R³ and R⁴ can collectively represent acarbon-carbon bond, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, heterocycle, or aryl substituent, whichsubstituent can be substituted or unsubstituted as well.

[0064] Suitable neutralizing agents include, without limitation, alkalihydroxides, such as sodium hydroxide, potassium hydroxide, lithiumhydroxide, ammonium hydroxide; alkali carbonates and bicarbonates, suchas sodium bicarbonate, potassium bicarbonate, and the like; as well asorganic bases such, as dimethylethanol amine and triethanol amine.Although any commercially available neutralizing agent and concentrationthereof will suffice, the neutralizing agent is preferably a 0.5M,0.75M, 1M, 1.25M or 1.5M solution of sodium hydroxide.

[0065] To this end, the chemistry and conditions required forneutralization of the gamma-keto carboxylate substituents would bereadily known to one of ordinary skill and need not be discussed atlength herein. Therefore, it will be appreciated that arriving at theoptimum process conditions for achieving the desired degree and kind ofneutralization will require no more than routine experimentation.However, in a preferred embodiment, the neutralizing agent is used in anamount and strength sufficient to provide a resulting pH of at least 8.

[0066] At this point, it should also be understood that, if desired, theresulting surface modified carbonaceous material, either before or afterthe optional neutralization step, can be washed with distilled water,filtered and/or dried in order to obtain substantially purified and/orisolated surface modified product.

[0067] In an alternative aspect, the present invention also provides forseveral surface modified carbonaceous materials that result from theaforementioned process. To this end, it will be appreciated uponpracticing the present invention that the surface modified carbonaceousmaterials resulting therefrom exhibit several advantageously improvedcharacteristics over those previously obtained in the art.

[0068] Accordingly, in one embodiment, the invention provides a surfacemodified carbonaceous material comprising a plurality ofgamma-keto-carboxyl substituents of the general formula—(CO)—CR¹R³—CR²R⁴—(CO)OM surface bonded thereto, wherein M is hydrogenor a cationic species as defined herein, and wherein R¹, R², R³, and R⁴can be independently selected from hydrogen, hydroxyl, amino, trimethylamino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, or heterocycle substituent.Additionally, any one or more combination of R¹ and R², R¹ and R⁴, R³and R² or R³ and R⁴ can collectively represent a carbon—carbon bond,C₁-C₂₀ alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, heterocycle, or aryl substituent, which substituent can besubstituted or unsubstituted as well.

[0069] For example, in one embodiment, the gamma-keto-carboxylcontaining functional group is derived from a maleic anhydride such thatR3 and R4 collectively represent a carbon-carbon bond and such that thegamma-keto functional group has the general formula:

—(CO)—CR¹═CR²—(CO)—OM,

[0070] wherein R¹ and R² are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent, and wherein the substituents can be substitutedor unsubstituted. In accordance with this embodiment, R¹ and R² arepreferably each hydrogen.

[0071] In an alternative embodiment, the gamma keto carboxyl containingfunctional group is derived from a succinic anhydride such that R3 andR4 each independently represent hydrogen and such that the gamma-ketofunctional group has the general formula:

—(CO)—CHR¹—CHR²—(CO)—OM,

[0072] wherein R¹ and R² are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent, and wherein the substituents can be substitutedor unsubstituted. Once again, in accordance with this embodiment, R¹ andR² are each preferably hydrogen.

[0073] In still another embodiment, the surface bondedgamma-keto-carboxyl containing functional group is derived from aphthalic anhydride such that R¹, R³, R², and R⁴ collectively representan aryl substituent and such that the gamma-keto functional group hasthe general formula:

[0074] wherein “X” represents the carbonaceous material, wherein R⁵ andR⁶ can be positioned on any carbon within the six member ring and areindependently selected from hydrogen, hydroxyl, amino, trimethyl amino,sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, or heterocycle substituent, and whereinthe substituents can be substituted or unsubstituted. Once again,similar to the previously described embodiments, R⁵ and R⁶ arepreferably each hydrogen.

[0075] As with the process aspects described above, the carbonaceouscompound or material can again be any carbonaceous material or compoundprovided it contains sufficient C—H edge sites capable of interactingwith a suitable anhydride under conditions effective to provide adesired surface modified carbonaceous material having a plurality ofsurface bonded gamma-keto-carboxyl functionalities.

[0076] Accordingly, it is preferred that the carbonaceous material havea surface area of at least approximately 25 m²/g as measured byASTM-D4820. In a more preferred embodiment, when measured by ASTM-D4820,the carbonaceous material will have a surface area of at leastapproximately 100 m²/g. In still a more preferred embodiment, thesurface area of the carbonaceous material will be greater thanapproximately 200 m²/g when measured according to the ASTM-D4820 method.

[0077] Specific examples of suitable carbonaceous materials againinclude, without limitation, carbon fiber, activated charcoal, finelydivided carbon, carbon black, graphite, fullerinic carbons, andnanocarbons. In a preferred embodiment, the carbonaceous material is acarbon black having a surface area greater than approximately 200 m²/gand an oil adsorption rate of at least 60 ml/100 g as measured byASTM-D2414.

[0078] According to the invention, the degree of surface modification orlevel of gamma-keto-carboxyl substitution can be measured by XPS (X-rayPhotoelectron Spectroscopy). More specifically, XPS can be used tomeasure the surface atomic concentration of oxygen species surfacebonded to a carbonaceous material prior to the surface modificationprocess of the present invention and as well as after surfacemodification. To that end, the gamma-keto surface modified carbonaceousmaterials of the present invention preferably have a surface atomicconcentration of oxygen surface bonded thereto greater than at leastapproximately 1.5%. In a more preferred embodiment, the surface atomicconcentration of oxygen surface bonded thereto is greater than at leastapproximately 2%, 3%, 4%, 5%, 6%, 7% or even 8%. It is understoodhowever, that the level of surface modification or substitution achievedwill ultimately be dependent on a number of variables, including thesurface area of the initial carbonaceous material. That is to say, thelevel of surface modification will typically increase relative to anincrease in the initial surface area of the carbonaceous material.

[0079] For example, with specific reference to the figures, FIG. 1illustrates the surface atomic concentration of the carbon black used toprepare the surface modified carbonaceous material of example 1. Asillustrated, the surface atomic concentration of oxygen is approximately1.2% prior to incorporation of the surface bonded gamma-keto-carboxylfunctional groups of the present invention. Similarly, FIG. 4 furtherillustrates the relative distribution and types of those oxygen speciessurface bonded to the unmodified carbon black of Example 1.

[0080] Turning now to FIG. 2, it is shown that the surface atomicconcentration of oxygen surface bonded to the modified carbonaceousmaterial prepared in Example 1 is approximately 8.0%. Furthermore, FIG.5 also illustrates the relative distribution and types of those oxygenspecies surface bonded to the carbonaceous material of Example 1 as aresult of the surface bonded gamma-keto-carboxyl containing functionalgroups.

[0081] Finally, FIG. 3 further illustrates that the surface atomicconcentration of oxygen surface bonded to the modified carbonaceousmaterial prepared in Example 2 is approximately 8.3%. Furthermore, FIG.6 also illustrates the relative distribution and types of those oxygenspecies surface bonded to the carbonaceous material of Example 2 as aresult of the surface bonded gamma-keto-carboxyl containing functionalgroups.

[0082] Among the several advantages that are obtained by practicing thepresent invention, the surface modified carbonaceous materials of thepresent invention exhibit an improved storage stability anddispersibility in aqueous and waterborne formulations. Specifically,when tested after storage periods of at least one week, one month andeven three months, an aqueous dispersion containing the surface modifiedcompounds of the present invention will exhibit substantially no visibleflocculation.

[0083] Likewise, after similar storage periods of at least one week, onemonth and even three months, an aqueous dispersion of a surface modifiedcarbonaceous material as described herein will advantageously passthrough a filter having a mesh size in the range of from approximately 8microns to approximately 10 microns, such as a Whatman #42 filter paper,leaving substantially no visible particulate residue.

[0084] Accordingly, these and other advantageous properties of thesurface modified compounds described herein facilitate their viabilityin several aqueous formulations. As such, in still another aspect, thepresent invention further provides several end use formulations for thesurface modified carbonaceous materials set forth above.

[0085] To this end, the present invention also provides an aqueouscomposition comprising a surface modified carbonaceous material as setforth above and water. The self dispersibility and long term stabilityof a surface modified carbon black according to the present invention isparticularly suited for this embodiment as it can be used to provide awaterborne ink formulation suitable for use in, among otherapplications, inks and in particular, ink jet printing and recordingtechnology.

[0086] To this end, when an ink dispersion is used in ink jetapplications, it is necessary to eject the ink in the form of stabledroplets through a minute orifice in the ink jet printing head ordevice. Therefore, it is very important that the ink formulation, andthe pigment dispersion contained therein, remain dispersed and stable soas not to flocculate and potentially clog the orifice. Advantageously,the self-dispersing surface modified carbonaceous materials of thepresent invention remain stable indefinitely when dispersed inwaterborne systems. Additionally, these aqueous dispersions do notrequire the use of additional dispersing agents to remain stable, whichmay undesirably increase the viscosity of such a formulation.

[0087] When the surface modified compounds, compositions and materialsof the present invention are utilized in an aqueous dispersion, thesurface modified carbonaceous material, e.g., carbon black, cansurprisingly be present in an amount of from approximately 1 wt % toapproximately 40 wt. % relative to the entire aqueous dispersion. In apreferred embodiment, the dispersion can comprise in the range of fromapproximately 10 wt. % to approximately 40 wt. % of the gamma-ketosurface modified carbon black. Furthermore, as indicated above, theaqueous dispersion advantageously remains stable indefinitely,exhibiting substantially no visual flocculation.

[0088] Likewise, an aqueous dispersion according to these embodimentscan comprise water in the range of from at least approximately 10% toapproximately 99% by weight of the aqueous dispersion.

[0089] If desired, aqueous dispersions and formulations comprising thesurface modified carbonaceous materials of the present invention canfurther comprise one or more humectants selected from ethylene glycol,diethylene glycol, propylene glycol, dipropylene glycol, polyethyleneglycol, polypropylene glycol, alcohol derivatives such as ethanol,propanol, isopropanol and the like, and cellosolve. It will beappreciated that the humectant is optionally introduced as a means tomaintain a substantially constant moisture content of the aqueousdispersions and formulations.

[0090] Additionally, a waterborne formulation or dispersion according tothe present invention can optionally contain one or more additionaladditives such as a polymer binder; e.g., Joncryl J-61 (Acrylic polymer,manufacture and available from S. C. Johnson Wax.), surfactants such asSurfynol 695 or Surfynol 7608 (manufactured by Air Products, Allentown,Pa.) and one or more biocide compositions.

[0091] To this end, the polymer binder acts as a film forming componentallowing a formulation such as an aqueous ink, to have substantialfastness and staying potential thus allowing the ink to bind to themedium once water and other optional solvents have evaporated.

[0092] Additionally, the incorporation of an optional biocide componentmay also be desired in order to control and/or prevent the potentialgrowth of algae and other microorganisms, which are typically prone todevelop in an aqueous system or formulation.

[0093] It will be appreciated that the aqueous dispersions comprisingthe surface modified carbonaceous materials of the present invention canbe prepared using any milling or dispersing machine known to one ofordinary skill in the art, including without limitation, shear stressmachines such as a two or three roll mill, machines which dispersepigment particles with impact strength caused by the collision betweenmedia such as glass beads, zirconia beads, steel beads, agate beads,such as a ball mill or pearl mill, or even with machines that finelydisperse pigment particles with a collision force or a shear stressamong the pigment particles or between the pigment particles and avehicle or a wall surface, such as a kneader or an extruder.

EXAMPLES

[0094] The following examples are put forth so as to provide those ofordinary skill in the art with a complete disclosure and description ofhow the compounds, compositions, articles, devices and/or methodsclaimed herein are made and evaluated, and are intended to be purelyexemplary of the invention and are not intended to limit the scope ofwhat the inventors regard as their invention. Efforts have been made toensure accuracy with respect to numbers (e.g., amounts, temperature,etc.); however, some errors and deviations may have occurred. Unlessindicated otherwise, parts are parts by weight, temperature is degreesC. or is at ambient temperature, and pressure is at or near atmospheric.

[0095] The amount or property of a compound as provided herein meanssuch amount as that capable of performing the function of the compoundor property for which an amount is expressed. As will be pointed outbelow, the exact amount required will vary from process to process,depending on recognized variables such as the compounds employed and theprocessing conditions observed. However, an appropriate amount may bedetermined by one of ordinary skill in the art using only routineexperimentation.

Example 1 Surface Modification of Carbon Black with Succinic Anhydride

[0096] 100 grams of Carbon Black (Raven 2500 Ultra, manufactured byColumbian Chemical Company, Marietta, Ga., U.S.A.) having a surface areaof 270 m²/g as measured by ASTM-D4820 and an oil absorption of 67 ml/100g as measured by ASTM-D2414, was added to a 3 necked flask containing250 mL of dimethyl acetamide. A solution of 10 grams succinic anhydrideand 13.4 grams of anhydrous aluminum chloride in 50 mL of dimethylacetamide was added to the carbon black/dimethyl acetamide slurry whilecontinuously stirring the ensuing mixture. The reaction mixture was thenstirred for an additional 2 hours at room or ambient temperature. Theresulting surface modified carbonaceous material was then filtered andwashed with distilled water.

[0097] After the initial filtration and washing, the surface modifiedcarbon black was then redissolved in 300 mL of distilled water andneutralized with 1M sodium hydroxide solution. Once again, thisresulting slurry was filtered, and then dried at approximately 110° C.The final product contained a plurality of surface bondedgamma-keto-carboxyl functionalities of the general formula:

—(CO)—CH₂—CH₂—(CO)—ONa.

Example 2 Surface Modification of Carbon Black with Phthalic Anhydride

[0098] 100 grams of Carbon Black (Raven 2500 Ultra, manufactured byColumbian Chemical Company, Marietta, Ga., U.S.A.) having a surface areaof 270 m²/g as measured by ASTM-D4820 and an oil absorption of 67 ml/100g as measured by ASTM-D2414, was added to a 3 necked flask containing250 mL of dimethyl acetamide. A solution of 15 grams phthalic anhydrideand 13.4 grams of anhydrous aluminum chloride in 50 mL of dimethylacetamide was added to the carbon black/dimethyl acetamide slurry whilecontinuously stirring the ensuing mixture. The reaction mixture was thenstirred for an additional 2 hours at room or ambient temperature. Theresulting surface modified carbonaceous material was then filtered andwashed with distilled water.

[0099] After the initial filtration and washing, the surface modifiedcarbon black was then redissolved in 300 mL of distilled water andneutralized with 1M sodium hydroxide solution. Once again, thisresulting slurry was filtered, and then dried at approximately 110° C.The final product contained a plurality of surface bondedgamma-keto-carboxyl functionalities of the general formula:

Example 3 Sample Waterborne Dispersion Formulation

[0100] A sample waterborne dispersion formulation for use in an aqueousflexographic printing system would be prepared using a surface modifiedcarbon black as prepared in Example 1. The formulation would comprise:Water: 20.4 wt % Isopropyl Alcohol: 3.7 wt. % Sulfonated Carbon Black ofExample. 1: 14.8 wt. % Joncryl J-61 (Acrylic polymer, 61.1 wt. %obtained from S. C. Johnson Wax)

Example 4 Sample Ink Jet Formulation

[0101] A sample ink jet formulation for use in an ink jet printingsystem would be prepared using a surface modified carbon black asprepared in Example 1. The formulation would comprise: Water 73.55 wt. %Glycerol 8.00 wt. % Diethylene Glycol 10.00 wt. % Surfynol 695 (Obtainedfrom Air Products, 3.00 wt. % Allentown, Pennsylvania) Surfynol 7608(Obtained from Air Products, 2.50 wt. % Allentown, Pennsylvania)Sulfonated Carbon Black of Ex. 1 2.75 wt. % Biocide 0.20 wt. %

[0102] Throughout this application, where various publications arereferenced, the entire disclosures of these publications are herebyincorporated by reference into this application for all purposes.

[0103] While this invention has been described in connection withpreferred embodiments and specific examples, it is not intended to limitthe scope of the invention to the particular embodiments set forth, buton the contrary, it is intended to cover such alternatives,modifications, and equivalents as may be included within the spirit andscope of the invention as defined by the appended claims. For example,there are numerous variations and combinations of components and orconditions, e.g., the carbonaceous material, solvent, anhydride,reaction conditions and the like that can be used to optimize theresults obtained from the described embodiments. To this end, oneskilled in the art will appreciate that in practicing the presentinvention, only reasonable and routine experimentation will be requiredto optimize such conditions.

What is claimed is:
 1. A surface modified carbonaceous material,comprising a plurality of gamma keto carboxyl containing functionalgroups of the general formula —(CO)—CR¹R³—CR²R⁴—(CO)OM surface bondedthereto, wherein R¹, R², R³, and R⁴ independently or collectivelyrepresent hydrogen, hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀alkyl, C₂-C₂₀ alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, heterocycle, carbon-carbon bond, or aryl substituent,wherein the substituents can be substituted or unsubstituted, andwherein M is a hydrogen or a cationic species.
 2. The material of claim1, wherein the carbonaceous material is carbon fiber, carbon black,graphite, finely divided carbon, activated charcoal, fullerinic carbon,or nanocarbon.
 3. The material of claim 1, wherein the gamma ketocarboxyl containing functional group is a maleic acid derivative havingthe general formula: —(CO)—CR¹═CR²—(CO)—OM, wherein R¹ and R² areindependently selected from hydrogen, hydroxyl, amino, trimethyl amino,sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, or heterocycle substituent, wherein thesubstituents can be substituted or unsubstituted.
 4. The material ofclaim 1, wherein the gamma keto carboxyl containing functional group isa succinic acid derivative having the general formula:—(CO)—CHR¹—CHR²—(CO)—OM, wherein R¹ and R² are independently selectedfrom hydrogen, hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent, wherein the substituents canbe substituted or unsubstituted.
 5. The material of claim 3, wherein R¹and R² are hydrogen.
 6. The material of claim 4, wherein R¹ and R² arehydrogen.
 7. The material of claim 1, wherein the surface bonded gammaketo carboxyl containing functional group is a phthalic acid derivativehaving the general formula:

wherein “X” represents the carbonaceous material, wherein R⁵ and R⁶ canbe independently positioned on any carbon within the six member ring andare independently selected from hydrogen, hydroxyl, amino, trimethylamino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, or heterocycle substituent, and whereinthe substituents can be substituted or unsubstituted.
 8. The material ofclaim 7, wherein R⁵ and R⁶ are hydrogen.
 9. The material of claim 1having a surface area of at least approximately 200 m2/g.
 10. Thematerial of claim 1, wherein the carbonaceous material is carbon black.11. The material of claim 1, wherein the cationic species is selectedfrom the group consisting of sodium, lithium, ammonium and potassium.12. The material of claim 1, wherein M is sodium.
 13. The material ofclaim 1, wherein the material exhibits substantially no vissibleflocculation when dispersed in an aqueous medium after a period of atleast approximately three months.
 14. A process for the manufacture of asurface modified carbonaceous material comprising a plurality ofgamma-keto-carboxyl containing functional groups surface bonded thereto,comprising the steps of: a) introducing a carbonaceous material and ananhydride into a suitable solvent; and b) reacting the carbonaceousmaterial with the anhydride under conditions effective to provide asurface modified carbonaceous material comprising a plurality ofgamma-keto-carboxyl containing functional groups having the generalformula —(CO)—CR¹R³—CR²R⁴—(CO)—OH surface bonded thereto, wherein R¹,R², R³, and R⁴ independently or collectively represent hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₂-C₂₀alkenyl, C₂-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl,heterocycle, carbon-carbon bond, or aryl substituent, wherein thesubstituents can be substituted or unsubstituted.
 15. The process ofclaim 14, wherein the carbonaceous material is carbon fiber, carbonblack, graphite, finely divided carbon, activated charcoal, fulleriniccarbon or nanocarbon.
 16. The process of claim 14, wherein thecarbonaceous material is carbon black.
 17. The process of claim 14,wherein the anhydride is a succinic anhydride of the general formula:

wherein R¹ is a hydrogen, hydroxyl, amino, trimethyl amino, sulfonate,C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkenyl, or heterocycle substituent, wherein the substituents canbe substituted or unsubstituted.
 18. The process of claim 17, wherein R¹and R² are hydrogen.
 19. The process of claim 14, wherein the anhydrideis a phthalic anhydride of the general formula:

wherein R⁵ and R⁶ can be independently positioned on any carbon withinthe six member ring and are independently selected from hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocycle substituent, and wherein the substituents can be substitutedor unsubstituted.
 20. The process of claim 19, wherein R¹ and R² arehydrogen.
 21. The process of claim 14, wherein the anhydride is a maleicanhydride of the general formula:

wherein R¹ and R² are independently selected from hydrogen, hydroxyl,amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, or heterocyclesubstituent, and wherein the substituents can be substituted orunsubstituted.
 22. The process of claim 21, wherein R¹ and R² arehydrogen.
 23. The process of claim 14, wherein the gamma keto carboxylcontaining functional group is a succinic acid derivative having thegeneral formula: —(CO)—CHR¹—CHR²—(CO)—OH, wherein R1 is hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C1-C20 alkyl, C1-C20alkenyl, C1-C20 alkynyl, C3-C7 cycloalkyl, C3-C7 cycloalkenyl, orheterocyclic substituent, wherein the substituents can be substituted orunsubstituted.
 24. The process of claim 23, wherein R¹ and R² arehydrogen.
 25. The process of claim 14, wherein the gamma keto carboxylcontaining functional group is a maleic acid derivative having thegeneral formula: —(CO)—CR¹═CR²—(CO)—OH, wherein R¹ is hydrogen,hydroxyl, amino, trimethyl amino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀alkenyl, C₁-C₂₀ alkynyl, C₃-C₇ cycloalkyl, C₃-C₇ cycloalkenyl, orheterocyclic substituent, wherein the substituents can be substituted orunsubstituted.
 26. The process of claim 25, wherein R1 and R2 arehydrogen.
 27. The process of claim 14, wherein the carboxylatecontaining functional group is a phthalic acid derivative having thegeneral formula:

wherein “X” represents the carbonaceous material, wherein R⁵ and R⁶ canbe independently positioned on any carbon within the six member ring andare independently selected from hydrogen, hydroxyl, amino, trimethylamino, sulfonate, C₁-C₂₀ alkyl, C₁-C₂₀ alkenyl, C₁-C₂₀ alkynyl, C₃-C₇cycloalkyl, C₃-C₇ cycloalkenyl, or heterocycle substituent, and whereinthe substituents can be substituted or unsubstituted.
 28. The process ofclaim 27, wherein R5 and R6 are hydrogen.
 29. The process of claim 14,wherein the suitable solvent comprises dimethylacetamide,dimethylsulfoxide or dimethyl formamide.
 30. The process of claim 14,wherein the conditions of step b) comprise the presence of a suitablecatalyst.
 31. The process of claim 30, wherein the catalyst is anhydrousaluminum chloride.
 32. The process of claim 14, further comprising: c)treating the surface modified carbonaceous material produced in step b)with a neutralizing agent under conditions effective to provide asurface modified carbonaceous material comprising a plurality ofgamma-keto-carboxyl containing functional groups having the generalformula —(CO)—CR¹R³—CR²R⁴—(CO)—OM surface bonded thereto, wherein M is acationic species.
 33. The process of claim 32, wherein the cationicspecies is selected from ammonium, sodium, potassium and lithium. 34.The process of claim 32, wherein M is sodium.
 35. The process of claim32, wherein the neutralizing agent is sodium hydroxide solution having aconcentration in the range of from approximately 0.75M to approximately1.5M.
 36. The process of claim 32, further comprising: d) filtering andsubstantially drying the surface modified carbonaceous material producedin step c) at a temperature of at least approximately 100° C.
 37. Anaqueous composition, comprising the surface modified material of claim 1and water.
 38. The composition of claim 37, wherein the composition isan ink and wherein the composition further comprises at least oneacrylic polymer and an organic solvent.
 39. The composition of claim 37,wherein the composition is an aqueous dispersion and wherein the surfacemodified carbonaceous material is a surface modified carbon black. 40.The composition of claim 39, wherein the surface modified carbon blackis present in an amount in the range of from approximately 1.0 wt. % toapproximately 40.0 wt % relative to the entire aqueous composition. 41.The material produced by the process of claim
 14. 42. The materialproduced by the process of claim
 32. 43. The material of claim 42,wherein M is ammonium, sodium, potassium or lithium.
 44. The material ofclaim 42, wherein M is sodium.